Android-Service定义与调用

public class FirstService extends Service {
    public FirstService() {
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        return null;
    }
    //Service 被启动时回调该方法

    @Override
    public void onCreate() {
        super.onCreate();
        Log.v("sevtext","Service is Created");
    }
    //  Service 被启动时回调该方法
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d("sevtext", "Service is started");
        return START_STICKY;
    }
    //Service 关闭之前回调该方法
    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.d("sevtext", "Service is Destroyed");

    }
}

public class MainActivity extends AppCompatActivity {
    Button start, stop;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        start = (Button) findViewById(R.id.start);
        stop = (Button) findViewById(R.id.stop);
        //创建启动Service 的Intent
        final Intent intent = new Intent(this, FirstService.class);
        start.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //开始指定service
                startService(intent);
            }
        });
        stop.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //停止指定service
                stopService(intent);
            }
        });
    }
}